Hydrocarbons (e.g., methane, ethane, propane, etc.) can be pyrolyzed or cracked to synthesize hydrogen and/or to produce solid carbon materials, as well as higher order carbon substances. However, many processes used to produce these higher-order carbon substances require the use of catalysts, such as metal catalysts. Additionally, many processes also result in the presence of impurities or contaminants, such as metallic and/or corrosive contaminants that foul the equipment. Furthermore, many processes require additional complex steps to ensure a desired quality or purity of the resulting products.